But there's a type of mining that's worth more than these land-transforming mining techniques. It's called "urban mining." Generally, it means reusing waste from urban materials. But in this case it means mining the precious metals from discarded electronics, or e-waste.

These "deposits" of e-waste contain precious metals "40 to 50 times richer than ores mined from the ground," according to a report from the Global e-Sustainability Initiative (GeSI) and United Nations University. And with 320 tons of gold and more than 7,500 tons of silver used to create more electronics each year, the value alone from those two precious metals is $21 billion.

But what's troubling is that only 15% of these valuable metals are recovered from e-waste in both developing and developed countries.

“More sustainable consumption patterns and material recycling are essential if consumers continue to enjoy high-tech devices that support everything from modern communications to smart transport, intelligent buildings and more,” said Luis Neves, Chairman of GeSI, in a statement.

There appears to a big opportunity for an entrepreneur out there to make a lot of money and run a business that has sustainability at its core.